The classical reparametrization-invariant SU(2) self-interactions of a test string are analyzed. Dynamically noncollapsing loop configurations in real space and on the intrinsic $S_2$ manifold are shown to exist, reflecting a combined effect of non-Abelian charges and currents. The dynamics leads naturally to a double-well "Weierstrass" potential whose minima specify two discrete configurations in the internal space.

• Received 29 June 1988

DOI:https://doi.org/10.1103/PhysRevLett.61.1450